SDS Board with all onboard parts and instructions, note this is not a built board you must build it yourself. This board replaces the 4 large can capacitors and several power resistors as well as the bias selenium filament rectifier and B+ diodes in the Fisher 500C receiver. Exact replacements for the original can capacitors are impossible to find. The values needed can be built up with various replacement caps, but the installation of all the needed capacitors tends to make the amplifier messy, and this particular unit is already very busy inside and finding room for the extra capacitors can be difficult. This circuit board uses readily available circuit board mounted capacitors. There is a large range of values and voltages available in this form factor. The board easily holds similar capacitor values to the original can caps with room to spare. The capacitor values can be increased substantially and still fit on the board and in the amplifier. This board bolts to the 8-32 power transformer mounting bolts using 3/4 threaded standoffs. Includes all onboard parts.